To most users, the improvements in Windows Phone 8 will initially appear relatively few in number compared to the jumps made by its bigger brother, Windows 8. But combined together, the new release is a compelling and deep upgrade.

Most obviously, the start screen is now more flexible and customisable than ever. For a start, it is wider - taking up the whole screen - which makes it feel less claustrophobic. More importantly, the so-called 'Live Tiles' which display animated information including photographs, weather, messages and music can now be shrunk or enlarged based on their importance to you. There are also a host of new 'theme' colours - 20 in total.

It makes for a much more attractive homescreen, and if you're keen on customising your phone you'll enjoy the chance to mould your device to your needs. Similarly the swipe-left gesture to bring up your main list of apps remains, and the apps list is as clean and clear as ever.

The lock screen is also much more customisable. It is now possible to choose which apps show detailed status updates - whether that's your inbox, a weather app or something else.

Other consumer-facing features in the new OS include enhanced background multi-tasking, voice recognition, better SD card support, a new Wallet hub to integrate NFC payments and loyalty cards and closer integration with VOIP and video calling services like Skype into the main Phone application - which is handy.

Xbox Music is also closely integrated into the OS, with free music streaming, syncing across devices (including Windows 8 desktops and Xbox) and access to a music store with more than 18 million songs. You can also pay for a subscription to download tracks for use offline.

Backup is also improved, with the ability to save pretty much your entire phone and restore it onto a new device, if your phone is lost or stolen, for instance. There are also more options to control which of your photos and videos are uploaded onto SkyDrive, Microsoft's cloud data service.

Maps are now powered by Nokia, and added turn-by-turn navigation and offline map downloads.

The camera app has also been updated with a new 'lenses' feature, which integrates mini apps like a Camera Strip mode into the core Camera experience.

Kids Corner is a new feature which lets parents create dedicated start screens for their children to use without messing up the rest of the phone. You can choose to isolate certain apps, turn off data connectivity and change the layout of the screen to make it easier to use. It's a handy feature, and should be really useful for families.

Internet Explorer 10 is also integrated into the OS, and in general it's a fast and capable browser, with more options for data encryption and performance boosts when handling HTML 5 and JavaScript.

Under the hood there are also some major upgrades. Windows Phone 8 now supports multi-core CPUS up to an insane 64 cores, as well as multiple resolutions. The mobile OS is also running the same kernel as Windows (not Windows CE) meaning it should be easier for developers to port apps over from the main OS to the phone. Combined, these updates open the possibility for bigger and more powerful games and other apps.

Microsoft has also added over-the-air OS updates, and a guaranteed 18 months of compatibility for new hardware - which isn't soon enough for current Windows Phone users left out of the new upgrade.

On security, Microsoft has brought Windows features like disk encryption, and built SmartScreen into Internet Explorer to make it more difficult for malware to target the platform.